Cellular telephone system that uses position of a mobile unit to make call management decisions

ABSTRACT

A cellular telephone system has call management decisions made based on the exact geographic location of the mobile unit. These call management decisions include billing and taxing decisions, cell site selection, frequency selection and even cellular system selection. The decisions are continuously updated during a call whereby decisions can be made and changed regardless of where a call originated. Cell site location, and even cellular system selection, can be made in a specific manner to best serve the needs of the mobile user, the cellular system as well as the public. It is even possible for a cellular system to locate one or more of its cell sites in the geographic area served by another cellular system. In some cases, cellular systems might even share cell sites.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. application Ser. No.09/662,613 filed Sep. 15, 2000, now allowed, which is a continuation ofU.S. application Ser. No. 08/848,082, filed Mar. 21, 1996, now U.S. Pat.No. 6,324,404, which is a continuation-in-part of U.S. application Ser.No. 08/555,884, filed Oct. 23, 1995, now U.S. Pat. No. 5,546,445, whichis a continuation-in-part of U.S. application Ser. No. 08/402,976, filedMar. 13, 1995, now abandoned, which is a continuation of U.S.application Ser. No. 08/057,833, filed May 7, 1993, now abandoned, whichis a continuation of U.S. application Ser. No. 07/813,494, filed Dec.26, 1991 and issued as U.S. Pat. No. 5,235,633. The disclosures of eachof these applications is fully incorporated herein by reference.Therefore, as used hereinafter, the term “prior art” refers to art thatis relevant prior to the invention dates associated with thisincorporated material.

FIELD OF THE INVENTION

The present invention relates to the general art of wirelessover-the-air communication, which includes cellular mobileradiotelephone (CMR) technology, and to the particular field of managingcommunication processes in a wireless over-the-air communication system.

BACKGROUND OF THE INVENTION

The present invention is concerned with wireless over-the-aircommunication using a plurality of transmit/receive cell sites or relaypoints. It should be understood that the transmit/receive relay pointscan be either land based or non-land based, such as satellite based, andthat as used herein, the term “cell site” or its equivalent refers toone of the relay points of the system. CMR (Cellular Mobile Radio) is anexample of one type of wireless over-the-air communication system thatcan be included in the present disclosure. It is understood that theterm CMR is not intended to be limiting, but is merely used as anexample for the purposes of discussion. It is also to be understood thatthe term “cellular telephone system” or its equivalents is intended tobe shorthand notation for the term “wireless over-the-air communicationssystem” and no limitation is intended by the use of the term “cellular.”Also, as used herein, the terms “CD (Communication Device)” and “MU(Mobile Unit)” are intended to include any device used to communicate inthe wireless over-the-air communication system. Also, the term “cellulartelephone system” is used for purposes of discussion but can include anyform of wireless over-the-air communication system. It is also notedthat many forms of communication are and will be conducted over thewireless over-the-air networks. Therefore, the present disclosure willrefer to a “communication process” which is intended to cover calls aswell as other forms of communication that can be conducted in thismanner.

CMR is a rapidly growing telecommunications system. The typical CMRsystem includes a multiplicity of cells. A particular geographic areacan be subdivided into a multiplicity of subareas, with each of thesubareas being serviced by a stationary transmitter/receiver setup. Thecells are set up to carry signals to and from mobile units in the rangeof the cell. If one cell site becomes too crowded, it can be dividedinto smaller cells, by a process known as cell site splitting. Anyparticular geographic area can become quite complicated with cellsoverlapping each other, and overlapping cells of other neighboringcellular systems. Further, null zones with inadequate coverage, or evenno coverage, can result. It is noted that the term “cellular” isintended to be a term of convenience, and is not intended to belimiting. The present disclosure is intended to encompass anycommunication system in which an overall area can be divided into one ormore subareas, and also to any communication system having at least someportion of the communications occurring over the air.

A typical CMR set up is indicated in FIGS. 1 and 2, and will bedescribed so an understanding of the problem to which this invention isdirected can be obtained.

A typical cellular telephone unit having a unique mobile identificationnumber stored in a suitable location such as an electrically erasableprogrammable read-only memory (not shown). Telephone units of this kindare known to those skilled in this art, and thus will not be describedin detail.

The telephone unit includes a handset 4 having a keypad 5 as well as aspeaker 6 and a microphone 7. A transceiver 8, ordinarily built into thetelephone unit, exchanges signals via an antenna 10 with a mobiletelecommunications switching office or MTSO 12 via a cell site 14. Aduplexer 15 connects the antenna to the transceiver. The cell site 14includes an antenna 16 connected to a control terminal 17 via atransceiver 18. The cell site 14 is connected to the MTSO via atransmission link 20. The Mobile Telephone Switching Office hashistorically been known as the center of the wireless over-the-aircommunications system. It is where the communication process managementdecisions are made, billing records are produced and where maintenanceactivities are initiated for wireless over-the-air communicationssystems. The MTSO is not a specific piece of equipment, but is comprisedof many individual pieces. The MTSO will contain a telephone switch,peripheral processors, adjunct processors, and various other informationgathering equipment used in the operation and management of a wirelessover-the-air communications system. Each of the different pieces ofequipment may directly or indirectly be involved providing the highestquality connection possible. The makeup of the MTSO therefore comprisesmany different pieces of equipment and many components, which can besupplied by different vendors. Therefore, communication processmanagement decisions made at the MTSO can actually, be made outside of aswitch and can be made in a cluster of nodes housed along the network oreven in separate cell sites. Therefore, as used herein the term MTSOreally refers to all of the systems, nodes, modules, equipment andcomponents that combine to define a wireless over-the-air communicationprocess management network, regardless of the physical or systemlocation of these elements. The term MTSO therefore is not intended tobe limiting to the “switching office” as it may have been viewed in theprior art. The term is intended to be much broader than that and toinclude any combinations of equipment, etc that may be connected withinthe communication processing network of the service provider. The termMTSO is one of convenience and is intended to include all theinformation processing hardware and software associated with thewireless over-the-air communication process management process within awireless over-the-air system, no matter where the hardware or softwareis located in the system. It is also noted that the term “intra-system”refers to actions and components within a particular system; whereas,the term “inter-system” refers to actions and components located outsidea particular system.

Referring to FIGS. 1 and 2, the operation of the CMR can be understood.The mobile unit M moves about the geographic areas covered by thevarious cells. As that mobile unit moves about, it decodes the overheadmessage control signals generated by various cell site control channels.The mobile unit locks onto the cell site that is emitting the strongestsignal. The mobile unit rescans channels periodically to update itsstatus. If, for example, a fixed-position land-based telephone T is usedto call the mobile unit, a signal is sent via landlines L, to thecentral office CO of a public/switched telephone system (PTSN) 12A. Thissystem then utilizes the switching network SN associated therewith tocall the MTSO 12 via a transmission link L1. The MTSO then utilizes itsown switching network and generates a page request signal to cell sitesvia transmission links, such as the transmission link 20. The cell sitewhich has been notified of the presence of the mobile unit M sends asignal back to the MTSO via the landlines or wireless links alerting theMTSO of the presence of the mobile unit. The MTSO then orders the mobileunit, via the notifying cell site, to tune to an assigned channel andreceive the communication process.

On the other hand, during communication process origination, the mobileunit rescans the control channels to determine which is the best serverbased on signal strength. Upon selecting the best server, the mobileunit transmits cell site information on the control channel receivefrequency and then receives a voice channel to tune to if the mobileunit is authorized to place a communication process.

As the mobile unit moves, the signal strength between that mobile unitand the originating cell site changes, and perhaps diminishes. Sincesignal strength is an inverse function of the square of the distancebetween the mobile unit and the cell site, signal strength can changerapidly and drastically as the mobile unit moves with respect to thecell site and therefore must be monitored closely. The MTSO has a signalstrength table, and signal strength from the mobile unit is constantlycompared to acceptable signal strength levels in the table. Such a tablecan be located in each cell site if desired.

Should signal strength diminish below a preset range, the MTSO generatesa “locate request” signal to all cell sites that neighbor the originalcell site. Each of such neighboring cell sites receiving a signal fromthe mobile unit signals the MTSO, and the signal strengths from suchneighboring cell sites are checked against the signal strength table.The MTSO makes a decision as to which cell site should control thecommunication process, and notifies the original cell site to order themobile unit to retune to a voice channel of the new cell site.

As soon as the mobile unit retunes, the mobile unit completes thecommunication process via the new cell site channel. This transfer ofcontrol is known as a handoff.

Typically, governments grant rights to provide wireless communicationservices to a specified land area based on geographic boundaries. Sincewireless propagation does not end at exact geographic boundaries, manyconflicts have arisen between service providers as to which serviceprovider should provide service at the location from where theCommunication Process (CP) is being originated or received. Today, thereare no methods or procedures to resolve these issues. A CommunicationProcess (CP) can be defined as the exchange of information betweencommunication devices, such as, but not limited to, Analog or Digitalradiotelephones, digital data communications, analog or digital video,and the like.

When the initial wireless systems were built, they were constructedaround major metropolitan areas. This created service voids betweenmajor metropolitan markets. In these early systems, boundary serviceproblems did not arise because there were areas of “no service”buffering competing systems. Today, as rural systems fill in thepatchwork of nationwide coverage, network service provision boundarydisputes are becoming common. Prior to the Dennison, et al patent, U.S.Pat. No. 5,235,633 and the patents and applications depending therefromas continuations and continuations-in-part, the disclosures of which arefully incorporated hereinto by reference, and the invention disclosedherein, it was impossible to honor the exact geographic boundaries.Attempts are currently made to control coverage boundaries by installingdirectional antennas and adjusting cell site receive and transmitparameters. The methods used to match the system boundaries to thegeographic boundaries are not entirely successful due to the variationsin terrain, environment and limitations of antenna design and wirelesspropagation. A common result of these problems is inadequate wirelesssignal strength or null coverage and border disputes around thegeographic boundaries and hence poor service.

The incorporated material, including the Dennison et al patent disclosethat cell sites sometimes have overlapping coverage due to theaforementioned variations in terrain and environment, and propose asolution. While the proposed solution works well, there is still roomfor further improvement in the areas of cost, subscriber service,billing and taxing.

Furthermore, wireless propagation, such as but not limited to thecellular operating band of 800-900 MHz, is generally line-of-sitetransmission. This presents substantial challenges when choosing sitesin which to place wireless transmit/receive antennas. Boundariesassigned to service providers are based on maps depicting the geographicborders of service boundaries. The question arises in a disputedterritory of who will get to service the Communications Process (CP). Inthe past, it has been the cell site that can provide the highest signalstrength from the CD (Communications Device), not the provider that ownsthe legal territorial rights to the Communication Process (CP) that hasserviced the Communication Process (CP). Until the invention disclosedherein, the service provider that could receive the best signal wouldhandle the communication process (CP), and depending on whether theCommunication Process (CP) was handed off and/or depending on theagreement made between the wireless communication systems, possibly keepall of the revenue from the communication process CP. Additionally, withreal estate values being very high in established communities, cellsites are harder to construct and more expensive to build. Each cellsite must be optimized for the maximum effective coverage area toovercome the real estate problems encountered when constructing a cellsite. This in turn creates problems with overlapping coverage betweenwireless systems and thus disputes over which wireless system handlesthe communication process. Further, due to business considerations, itmay be economically advantageous for one wireless system to own a cellsite which is geographically located in the geographic area of anotherwireless system.

Cell sites are very expensive to install and maintain, so there is avery real savings for a service provider if fewer cell sites could beconstructed while also improving coverage. Another area that would beaffected by this is problems of quality service. This is because theservice provider has conflicting requirements. To provide good coveragenext to borders the provider would like to have high signal strength. Toallow for hand-offs between cell sites and networks the signal strengthneeds to “fade out” at just the right level near the border to invoke alow threshold to start a hand-off process. It would be ideal to havehigh signal strength right up to a geographic boundary and then drop offbeyond that boundary. However, at the present time, presently availablesystems do not permit this type of coverage.

Some areas inherently have wireless propagation problems, such asservice areas next to bodies of water or in steep valleys. Wirelesspropagation can provide some very undesirable results for a number ofreasons, some of which have been mentioned above and in the incorporatedmaterial. Therefore, there is a need to provide each network informationas to which system has a right to handle a Communications Process (CP).For instance, a communications device (CD) might attempt to select ageographically incorrect service provider. Therefore, there is a needfor a system that will permit a service provider to redirect thecommunication process to the geographically correct service provider,especially in a manner that is transparent to the Communications Device(CD) user.

Since cellular system geographic borders can be non-linear and can haveirregular shapes, problems can arise. Problems associated with irregularboundaries are indicated in FIG. 3. FIG. 3 graphically shows the problemof obtaining coverage for areas that have irregular boundaries. In thisfigure, areas A and C are serviced by Carrier X, and area B is servicedby Carrier Y. It is noted that areas A and C are intra-system withrespect to Carrier X and area B is intra-system with respect to CarrierY, while areas A and C are inter-system with respect to Carrier Y andarea B is inter-system with respect to Carrier X. It is also noted thatareas A and B could be covered by just one cell site each but theoverlap into adjacent territories would be difficult to resolve. Today,areas such as these would be split into two or more cell sites. Forinstance, Carrier X might elect to install three cell sites A1, A3 andA4 which provides a minimum of overlap into area B. Overlap is indicatedat the shaded areas. Therefore, there is a need for a system what wouldallow Carrier X to install a cell site with a larger coverage area suchas A2 (shown in dotted lines).

FIG. 4 shows a prior art attempt of providing sectored cells.

Using prior art technology requires installation of directional antennasto minimize the overlap into neighboring territory in order to resolve aborder issue. Since these antenna patterns cannot be made to followcurved geographic borders, sectors are installed and directed for thebest geographic coverage possible. This often involves obtaining a cellsite location close to the border and “shooting back” toward thewireless communication system's own territory. This can leave null zoneswhere cells back onto each other in an effort to keep signals fromoverlapping into neighboring territory. These null zones will haveeither poor quality service or even no service at all, thereby resultingin poor service. Therefore, there is a need to overcome this problem aswell.

FIGS. 5A and 5B illustrate a problem of how geographic terrain canaffect prior art systems. In FIGS. 5A and 5B, a small rural network A islocated just across the river from a large city C, which is part of aneighboring network B. The river defines the geographic and legal borderbetween these two systems. The city C is in another state just acrossthe river. In some river towns, there is a bluff on each side of theriver. The network A can place their cell sites very near the borderatop the bluff providing overlapping coverage into the city C. Network Awill get all the service of the neighboring community D further awayfrom the city C. Network A now has better line of cell site receptioninto the river valley with its corresponding traffic at river level thandoes network B who legally “owns” the territory. Network B would have toinstall additional cell sites in the river valley to obtain the samecoverage. Due to the stronger signal level provided by Network A,Network A will process a communications process (CP). The result is thatsubscriber's Communication Process (CP) may not be processed by thecorrect service provider.

Note in FIG. 5A that there are two service providers X and Y. Theinter-system boundary is shown as a dashed line down the middle of theriver. With a bluff on either side of the river, the cells can onlyservice the opposite bluff. This is shown where Y1 cell site cannot“see” the subscriber CD′ hidden below. Cell site Y1 can however find CD3in service provider X's territory. This issue denies revenue to thewireless communication system that has legal right to serve thesubscribers within its licensed geographic service boundaries. Prior artsystems are incapable of determining the geographic location of both thecommunications devices and their service boundaries and thus compromisequality of coverage. Therefore, there is a need to resolve this issue.

There is also need for providing a wireless over-the-air communicationsystem with the ability to adjust its coverage and billing as the mobileunit moves. This will permit the system to determine taxes based onwhere the communication process is actually being made as opposed to thecriteria used with the prior art. Still further, there is a need topermit a wireless over-the-air communication system to changefrequencies as the mobile unit moves whereby a single wireless serviceprovider can provide service to its subscribers regardless of frequency.

Still further, due to various business reasons, a single cell site mayadvantageously be used by more than one system. It will be necessary todetermine which wireless communication system bills the communicationprocess. Prior art systems cannot fully account for this.

Still further, if there is a service problem with a mobile unit, priorart systems are not able to accurately identify the exact geographiclocation of the unit when the problem arose. This makes it difficult forthe network to pinpoint coverage problems. Therefore, there is a needfor a wireless over-the-air communication system that permits a wirelesscommunication system to exactly and precisely identify the exactgeographic location of a mobile unit when a communication problemoccurs.

Still further, with the advent of emergency response networks that usetelephones, such as the E-911 systems, there is a need for a wirelessover-the-air communication system that can precisely locate a mobileunit and pass that information on to an emergency response system.

The location of an over-the-air system mobile unit making acommunication process can also be of use to law enforcement agencies.However, signal strength from one cell site does not provide suchlocation information with sufficient accuracy to be of the bestassistance to law enforcement agencies. Therefore, there is a need foran over-the-air communications network that can provide geographiclocation of a mobile unit during a communication process with accuracysufficient to satisfy law enforcement agencies. This information shouldbe rapidly updatable so a mobile unit can be tracked.

Since the CMR industry is growing rapidly, competition is growing.Therefore, it is in the best interest of a system to be able to providethe best service possible to its subscribers. One way of achieving thisobjective is to customize the service to the exact needs of eachsubscriber. This can be achieved by, among other things, customizing andvarying a billing rate plan for each subscriber. That is, the subscribermay be able to pay a lower rate when he is at work than he pays when heor she is at home. Therefore, there is need to a wireless over-the-aircommunication system that can vary rate plans and vary rates in a mannerthat will permit offering the best rate plan to each subscriber based onthat particular subscriber's use and needs. Still further, somecommunication processes must be handled in a special manner to accountfor environmental conditions, or system needs, such as down time for aspecific cell. Therefore, even if a communication process should behandled by a certain cell site, there may be times when thatcommunication process must be handled by another cell site. Therefore,there is need for a wireless over-the-air communication system that canaccount for special circumstances associated with a communicationprocess, and alter the system response when the mobile unit meets thecriteria for those circumstances, even if the communication process isalready in progress when the criteria are met.

SUMMARY OF THE INVENTION

It is a main object of the present invention to provide a wirelessover-the-air communications system that will permit a wirelesscommunication system to determine the most efficient and accurateservice to a mobile unit.

It is another object of the present invention to provide a wirelessover-the-air communications system that will permit a wirelesscommunication system to accurately bill a subscriber.

It is another object of the present invention to provide a wirelessover-the-air communications system that will permit a wirelesscommunication system to accurately determine taxes for a subscriber forthat subscriber's use of the system.

It is another object of the present invention to provide a wirelessover-the-air communications system that will be able to handle allcommunication processes legally permitted it.

It is another object of the present invention to provide a wirelessover-the-air communications system that will be able to handle allcommunication processes legally permitted it and to forwardcommunication processes that rightfully belong to another wirelesscommunication system while retaining billing and taxing of any portionof the communication process that belongs to it.

It is another object of the present invention to provide a wirelessover-the-air communications system that will be able to handle allcommunication processes legally permitted it based on geographicconstraints.

It is another object of the present invention to provide a wirelessover-the-air communications system that can bill a subscriber based onthe geographic location of communication process origination, and thencan update and alter that billing as the mobile unit moves.

It is another object of the present invention to provide a wirelessover-the-air communications system that can co-operate with otherwireless networks in handling a communication process.

It is another object of the present invention to provide a wirelessover-the-air communications system that can share cell sites with othernetworks while retaining its ability to bill and service its ownsubscribers.

It is another object of the present invention to provide a wirelessover-the-air communications system that can provide the most efficientand effective service to its subscribers and users.

It is another object of the present invention to provide a wirelessover-the-air communications system that can update any communicationprocess management parameter to account for instantaneous geographiclocation of a mobile unit.

It is another object of the present invention to provide a wirelessover-the-air communications system that can assign and re-assign acommunication process according to the location of the mobile unitduring the communication process.

It is another object of the present invention to provide a wirelessover-the-air communications system that can share geographic boundarieswith other wireless over-the-air service providers without borderissues.

It is another object of the present invention to provide a wirelessover-the-air communications system that can change and update itsoperating frequencies during a communication process.

It is another object of the present invention to provide a wirelessover-the-air communications system which can have the highest possiblesignal strength at its borders.

It is another object of the present invention to provide a wirelessover-the-air communications system which can identify the location of amobile unit when a service problem arises.

It is another object of the present invention to provide a wirelessover-the-air communications system that can efficiently work withemergency service providers.

It is another object of the present invention to provide a wirelessover-the-air communications system that can efficiently implement andutilize special rate plans.

It is another object of the present invention to provide a wirelessover-the-air communications system that can efficiently implement andutilize special requirements for a communication process.

It is another object of the present invention to provide a wirelessover-the-air communications system that can establish parameters forupdating mobile unit information based on the particular needs of themobile unit.

It is another object of the present invention to provide a wirelessover-the-air communications system that can establish time and/ordistance parameters for updating mobile unit information based on theparticular needs of the mobile unit.

SUMMARY OF THE INVENTION

These, and other, objects are achieved by a CMR system that allows theExact Geographic Location (EGL) of a communications device to be trackedand compared to geographic land data and information data and tocontinuously update this information during the communication processwhereby the proper and most efficient service is provided, includingproper communication process management and billing decisions. Withinthe scope of this invention is the ability to solve the above-mentionedproblems and achieve the above-mentioned objects. By knowing the exactgeographic location of a mobile unit during a communication process,competing service providers can locate their cell sites anywhere wherethe wireless reception will allow them to provide the best wirelesscoverage of their territory. The cell sites can even have overlappingcoverage, or be inside an adjacent wireless communication system'scoverage area. By knowing the location of the calling device at alltimes during the communication process, the wireless over-the-aircommunication system can configure the system to work together withother systems and wireless communication systems to process acommunication process correctly. Service can be provided by the properlicensed wireless communication system because the exact location of themobile unit is known at all times during the communication process.Propagation patterns and the like are not needed.

By way of background, the operation of a cellular system 20 is shown inFIGS. 6, 7 and 7A. The cellular system 20 uses positional dataassociated with the mobile unit M′ to make communication processmanagement decisions. To this end, the cellular system 20, while similarin all other respects to the cellular system illustrated in FIGS. 2 and3, includes means for accurately and precisely determining the exactposition of the mobile unit M′, and then further includes means forusing this positional information to determine which cell site is bestsuited to handle a communication process associated with that mobileunit M′.

The means for accurately determining the precise position of the mobileunit includes a Global Positioning System. The GPS includes satellites,such as satellite 22 in geostationary orbit about the earth. Each mobileunit further includes a GPS receiver 24 located between the duplexer andthe logic circuitry 25 of the mobile unit. The GPS receiver communicateswith the satellite 22 and the exact longitude and latitude of the mobileunit are determined. This information is sent to the MTSO via a cellsite, and the MTSO uses a look-up table such as disclosed in FIG. 9, todetermine which cell site is most appropriate for use by the mobileunit. The mobile unit communicates with cell sites using unused bits ofthe aforediscussed overhead messages to send its positional informationto the MTSO when the mobile unit is first activated. This positionalinformation is relayed to the MTSO by the first cell site to communicatewith the mobile unit. The MTSO then selects the cell site mostappropriate for the mobile unit and hands that mobile unit off to thatcell site. The cell sites transmit system service boundaries in theiroverhead messages that are interpreted by mobile units. The mobile unitsuse the location information supplied by the GPS receiver as opposed tosignal strength to determine which system to originate on. Communicationprocess termination can utilize the paging process as is currentlyutilized. A response from a mobile unit includes the locationinformation, and the designated control channel instructs the mobileunit to tune to one of its channels. A communication process in progressutilizes the overhead message of the voice channel to communicatelocation information. Once a mobile unit that is processing on aparticular cell site crosses a cell site boundary, it is instructed toperform a handoff to the cell site that is to service the new location.It is understood that the GPS is used as an example of the preferredsource of positional data; however, other sources similar to the GPS canbe used without departing from the scope of the present invention. Allthat is required is that the source of positional data be able togenerate precise and accurate locational data on a fixed or a rapidlymoving object. It is also helpful, but not absolutely required, that insome circumstances, such as triangulation, the CMR be only passivelyinvolved in the determination of the positional data.

The handoff process is similar to the present hand-off processes, exceptit will be controlled according to position of the mobile unit insteadof signal strength. This position information is used to determinecommunication process rating and taxing for billing purposes andcommunication process routing to make sure that the proper services forthat location are provided.

A “locate request” signal is not used, since the exact location of themobile unit is known to the MTSO. However, a signal strength method canalso be used in making communication process management decisions ifsuitable. Such a process would be used if the mobile unit moves into aprior art cellular system.

The hereinafter disclosed system has many advantages over the prior artsystems. Multiple layers of information can be generated and used. Thesystem using the invention disclosed herein and in the incorporatedmaterial may use many levels of mapping such as cell site selection,taxing, billing, special rate plans, and the mapping of E-911 calls toan appropriate service provider.

The above and other objects and advantages of the present inventionshall be made apparent from the accompanying drawings and thedescription thereof.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 illustrates a typical prior art mobile cellular telephone and itslink with a fixed cell site and an MTSO.

FIG. 2 illustrates a typical prior art cellular system in which a mobileunit can be connected with a fixed-position unit.

FIG. 3 illustrates an overlapping boundary problem with prior artsystems as well as a fading signal at the borders.

FIG. 4 illustrates a null zone problem associated with prior artsystems.

FIGS. 5A and 5B illustrate boundary issue problems between two prior artsystems separated by a natural boundary, such as a river.

FIG. 6 is a block diagram of a mobile unit of a wireless over-the-aircommunications system which incorporates a GPS location determiningsystem embodying the present invention.

FIG. 7 illustrates a wireless over-the-air communications systemincorporating a GPS position locating system for a mobile unitcommunicating with other units, such as the fixed-position unit shown.

FIG. 7A is a block diagram showing systems included in an MTSO.

FIG. 8 is a block diagram illustrating a flow chart for the wirelessover-the-air communications system embodying the present invention.

FIG. 9 is a block diagram showing a registration process used in thepresent invention.

FIG. 9A is a block diagram showing a communication process ratingprocedure used in the present invention.

FIG. 9B is a block diagram of a communication process routing processused in the present invention.

FIG. 10 is a diagram showing a billing process used in the presentinvention.

FIG. 11 illustrates the elimination of a null zone problem with a systemembodying the present invention.

FIG. 12 illustrates variable billing and/or taxing for a mobile unitusing the system of the present invention.

FIG. 13 illustrates how cell sites can be shared using the system of thepresent invention.

FIG. 14 illustrates how a cell site for one wireless over-the-aircommunication system can be located in the geographic boundary ofanother wireless communication system when the present invention is usedto manage communication processes made by a mobile unit.

FIG. 15 illustrates the solution to overlapping boundary problemsachieved by the present invention.

FIG. 16 illustrates how frequency of a communication process can bechanged using the system of the present invention during a communicationprocess and without the unit being aware that the frequency is beingchanged.

FIG. 17 illustrates the application of the present invention to ageographic area which includes several countries.

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments of the invention and,together with a general description of the invention given above, andthe detailed description of the embodiments given below, serve toexplain the principles of the invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

A representation of the logical flow that may occur in a wirelesscommunications system incorporating the use of exact geographic location(EGL) for the communication process management decisions is shown inFIGS. 8-10. The communication process management decisions are based oninformation provided by the communication device (CD) towards the fixedsystem and to the communications device from the fixed system. Thedescription of a sample communications process (CP) begins upon thepowering up of the communicating device and continues until thatcommunications process is completed.

When a communications device is powered up, block 101, the registrationprocess, block 102 is initiated. The registration process is detailed inFIG. 9. The first step in the registration process, block 102 is todetermine the exact geographic location, block 201 of the communicationsdevice via either GPS, block 202, signal strength, block 203, Loran,block 204, triangulation or other similar location means. Theinformation is used by the initial (Home) serving system and the exactgeographic location (EGL) is compared to the service boundaries, block205 for that home system. A determination is made as to whether or notthe Communications Device (CD) is located within the serving system'sboundaries via the means of communication data filed in the servingsystem, block 206. The communication data may include computerizedlatitude and longitude tables which are then compared to geographiclocation tables of service allocation. In the absence of comparativetables, algorithms may be run to determine the mapping of exactgeographic location (EGL) to service boundaries. If the CommunicationsDevice (CD) is located within the serving system's boundaries, the exactgeographic location (EGL) is reestablished, block 216 and recorded,block 217 for billing or other purposes. If the Communications Device(CD) is determined to be located outside of the serving system'sboundaries, then the exact geographic location (EGL) is compared to theneighboring system boundaries, block 208 and block 212 on an interactivebasis until the system that is authorized to serve the CommunicationsDevice (CD) at the current exact geographic location (EGL) isdetermined. In addition to the reference tables that assign the serviceprovider, the communication data, blocks 209, 213 also identifies themeans of transferring control of the Communications Device (CD) from onesystem to another. Once the correct system is identified, theCommunications Device (CD) is commanded to establish communications withthe proper cell site within the correct system 211, 215. An example ofthis would be commanding the Communications Device (CD) to tune to theneighboring system's control channel. A registration increment timer 103is then sent to the Communications Device (CD) informing it of theintervals 104 at which re-registration is required. This registrationprocess is continued through the period that the Communications Device(CD) is not in a Communication Process (CP) active state.

If a Communication Process (CP) were initiated then the registrationprocess, block 106, FIG. 9, would take place to update the exactgeographic location (EGL). Once the exact geographic location (EGL) isestablished the routing selection for the Communication Process (CP) isbegun, block 107. FIG. 9B shows that the first step is to identify theCommunications Device (CD), block 401 so that the servicecharacteristics, block 402 can be identified. A determination is thenmade as to whether or not service is to be provided, block 403. Ifservice is to be provided proper routing is selected, with the mostappropriate communications path to connect point A to point B isselected for the specific communication process based on the exactgeographic location (EGL) of the Communications Device (CD), block 404.This may include activities and decision to route communicationprocesses through land based networks, microwave, fiberoptic links andthe like to allow for cost effective or expeditious connections to beestablished. If service is to be denied, the wireless communicationsystem can direct the communication process to the appropriateannouncement, block 405 and if the Communication Process (CP) beinginitiated is determined not to be a 911 emergency call, block 406. If acommunication process is determined to be a 911 emergency call, then thesystem identifies the proper routing of the emergency communicationprocess, blocks 407, 408 and 409, and the communication process will bedirected to the proper emergency response system. The routing of thisemergency call should be accompanied by all of the information that ispertinent and available, blocks 410 and 411. If the exact geographiclocation (EGL) continues to change, updates should be sent to theserving emergency response system, block 412. If another emergencyresponse system needs to gain control of the call, the system will beable to establish a connection with the new emergency response system,block 413. This event is then recorded upon completion, block 414.

With communications established (FIG. 8), block 108, the exactgeographic location (EGL) may be stored for Communication Process (CP)management, billing purposes, and other identification needs, block 114.The stored exact geographic location (EGL) is then recorded forestablishing the origination point for billing purposes, block 109,emergency 911 call accounting, block 110, taxing purposes, block 111,rating the Communication Process (CP), block 112, or post communicationprocess subscriber service, block 113. The Communication Process (CP)rating process shown in FIG. 9A identifies the subscribercharacteristics, blocks 301 and 302. The recorded exact geographiclocation (EGL) is then compared to the Communication Process (CP) ratingtable, blocks 303 and 304 to select the correct rating, block 305 forthat communication process (CP). This information is then recorded forlater processing which may include application of taxes, CommunicationProcess (CP) billing rates, or any other information which could bematched to the exact geographic location (EGL) of the communicationprocess (CP). As the Communication Process (CP) continues, the exactgeographic location (EGL) is constantly updated, block 1 15 oralternately updated at various intervals, block 114 a, which intervalscan be changed based on the time and/or distance traveled by the mobileunit to meet system needs for efficient communication processmanagement, and these updated Communications Device (CD) locations areused for communication Process (CP) management, block 116, billingdecisions, block 119, and other real time processing uses, such as 911emergency calls made while a non-emergency communication process was inprogress, block 120, taxing, block 121, Communication Process (CP)rating, block 122, subscriber service, block 123, and frequencyselection, block 124. The intervals at which the updating occurs can bedetermined on a preset time, such as every minute, or can be determinedaccording to distance traveled by the mobile unit, such as every twentymiles, or the interval can be set according to the nearest border sothat the mobile unit will be monitored whenever it reaches a locationthat would cross over the border if the mobile unit traveled toward thatborder. In this manner, the billing information, the tax information andthe frequency of the communication process can be based on the locationof the communication process origination, but can also be continuouslyupdated and changed as the mobile unit moves during the communicationprocess whereby the exact rates and frequencies at any instant duringthe communication process can be applied to the communication process.As was discussed above, this will even permit separate networks to sharecell sites as even though a single cell site handles a communicationprocess, the location of the mobile unit will determine which systemreceives credit for the communication process and will handle thebilling and taxing of the communication process. Alternatively, thiswill permit separate cellular systems to locate their own cell siteswithin the geographic area of another cellular system, and may evenpermit several different systems to share a single cell site.

The cell site can re-direct a communication process to another cell siteunder certain circumstances. For example, even though a particular cellsite is chosen to handle a communication process, there may be specialcircumstances associated with a particular location that dictate allcommunication processes from that location be handled by a certain cellsite. Special environmental conditions may be one such specialcircumstance, cell sites under repair may be another specialcircumstance or other business reasons may dictate such re-directing ofcommunication processes. This redirecting can also occur for cellularsystems. That is, if a selected cell site is not owned by the cellularsystem having rights to the communication process made by the mobileunit at that particular location, the communication process could beredirected to another cellular system. In this manner, customization ofcellular service can be maximized with billing, taxing, frequency andthe like all being selected according to the exact needs of the mobileunit during the communication process, and changed as the needs of themobile unit change during the communication process. As discussed above,the preferred means for establishing the exact geographic location ofthe mobile unit includes a satellite communications system; however,other means can also be used.

All of this data collection and monitoring continues until theCommunication Process (CP) is completed, block 117. When theCommunication Process (CP) is complete, and exact geographic location(EGL) of the mobile unit is recorded for various data processing usesprior to the data record closure, block 118.

FIG. 10 shows how the billing information is passed along through anexternal billing system. The MTSO first generates Automatic MessageAccounting (AMA) files, usually in magnetic tape format, which holds allthe detailed records for communication processes processed from aparticular MTSO during that billing period. The AMA records are thenprocessed (formatted into database readable media) at the wirelesscommunication system's billing center which emerge as Call DetailRecords (CDR). Call Detail Records are the detailed accounting of allthe communication processes assigned to a subscriber's account. Theroaming and home reports are combined which are then processed assubscriber bills. It is here in the prior art system that any taxes maybe applied by the service provider or by the wireless communicationsystem. Ideally, taxes should be assessed based on the location of themobile unit when service is provided. This is not the case with priorart systems. For example, home communication processes are taxedaccording to either the billing address of the subscriber or the zipcode or business address of the service provider and roam communicationprocesses, that is communication processes made using a cell site thatis not in the mobile unit's home area, are taxed based on the billingaddress of the roam network or where the cell site is located thatservices the communication process. Any tax based on the cell sitelocation has the possibility of being in error, especially if the cellsite is located adjacent to a border. The prior art has failed to teachthe distinction between fixed location of hardware and exact geographiclocation (EGL) of the Communications Device (CD) for billing.

In the present system, the wireless communication system will obtain theinstant location of the Communications Device (CD) at the registrationprocess (FIG. 9). In a system where bills are processed externally,billing information combined with the location of on the Call DetailRecords can then be compared to lookup tables or algorithms that willassess the proper tax or billing rate depending on the location(origination, termination, duration, instantaneous location, or thelike) of the communication process.

If needed, the billing location codes could be recorded at some giveninterval (perhaps, for example, every minute, or after the mobile unithas traveled a certain distance) that would allow for updates andchanges to the billing code as the Communications Device (CD) movesthrough different territories or beyond interval distances which can becalculated directly in a GPS system or indirectly via vectorcalculations in other systems.

One of the additional features that can be provided by the system of thepresent invention is real time subscriber service (FIG. 8, block 123).Knowing the location of the Communications Device (CD) is important tothe wireless service provider to help solve some service problemsassociated with the wireless network.

Although billing and taxing issues are important to current land basedwireless communications systems service providers, these issues will beeven more important for satellite systems (see FIG. 17) because thefootprint of a satellite can cover many states or even different smallcountries such as in the European Community, with enormous taxgenerating capacity. With GPS location devices or Loran-C or any othertype of location technology used to locate the satellite mobile phones,the problem can be avoided using the system disclosed herein. The exactgeographic location of each subscriber unit will be carried along withvoice transmission to allow location of the billing unit to bedetermined for tax assessment billing.

The advantages realized by the present invention can also be understoodby comparing FIGS. 3-5 to FIGS. 11-16.

FIG. 11 shows the identical borders and cells as shown in FIG. 4.However, this time omnidirectional antennas are shown which improvecoverage but can cause overlap into a neighboring system. This overlapcan be handled as described above by each network having independentinter-system cells which map the exact geographic location (EGL) of theCommunications Device (CD) to determine which system will service theCP.

FIG. 13 shows still another configuration which could be utilized whereborders are concerned. Two or more bordering service providers coulderect single cells on or very near the border. Since the systems willtrack the exact geographic location (EGL) of each communications device(CD), it will know which service provider to connect the CommunicationProcess (CP) to. This system uses a routing processor after theCommunication Process (CP) has been accepted.

FIG. 14 shows a situation where the cell site from a competitive serviceprovider is inside their borders. As shown, cell site Z3 is in place inservice provider Q's territory. Communications Devices which arephysically located inside territory Z which come up on cell site Z3(communication device CD13) will be accepted. Communication device CD14which will come up on cell site Z3 will be redirected to the controlchannel of cell site Q2 since it lies within territory Q.

FIG. 15 shows the same territory depicted in FIG. 3 which in the priorart had many cells and many border overlap issues, which resulted, inprior art systems, in the service providers adding smaller cell sites tobreak up the coverage into smaller sells. FIG. 15 shows what can be donewith the inventive system to reduce the number of cell sites. By havingfewer cells, they will have to be of higher power which allows forbetter signal strength out at the borders. By using the inventive systemto manage the Communication Process, the correct system will handlecommunication processes even under conditions of overlapping coverageinto a neighbor's territory. To illustrate this, the signal values areshown in FIGS. 3 and 15 for cell site coverage of cell sites A1 and B1.In the prior art system (FIG. 3), each service provider will adjust itscell site to give some predetermined signal strength at the border. Asan example, this value is shown as −5 dB. This value will be as close tothe border as possible to invoke a hand-off to the neighboring serviceprovider (Note, communication device CD5 is at signal strength levels,A1=−2 dB, B1=−5 dB). However, the weaker the signal, the poorer theservice such as terminated communication processes. However, if acontrast is made with the signal strengths in the inventive system, itwill be found that higher values at the borders can be maintained whichresults in better service. For example, communication device CD6 signalstrength A1=1 dB, B1=5 dB. Since most borders are straight lines andwireless communication sometimes propagates in a radial fashion, priorart service providers cannot simply increase the cell site's power toprovide higher signal strength values at the borders. Therefore, if aprovider sets a cell site to hand off at a certain value, it willhand-off wherever the signal strength decreases to that level, which maybe a radial curve, which most times may not follow the geographicservice boundaries.

Therefore, as can be seen from the figures, if the provider were toincrease the signal strength in an area, it may result in more overlap.This overlap is not a problem with the inventive system since theservice boundaries are mapped to the exact geographic location (EGL) ofthe communications device (CD).

An example of another advantage realized with the present system is thatall communication processes may be processed through the tax data base,but the wireless communication system may have a select group ofsubscribers that are identified to pay a certain billing rate in aspecified geographic area which would constitute an additional loopthrough another look-up table. For example, as indicated in FIG. 16,company A has negotiated for an attractive airtime rate within itsplant's boundaries. This plant also resides in school district B whichhas assessed it own tax. The company employees will therefore enjoy theattractive rates while inside the plant and must pay the school tax onthose communication processes. But if those employees go beyond theplant, they will lose the lower rate. For instance, communication deviceCD8 may have a low pre-negotiated rate, but pay school district B andstate P taxes. Communication device CD9 pays the school district B andstate P taxes, and communication device CD10 pays only the state tax.Billing is continuously updated no matter where the communicationprocess originated as the mobile unit moves.

Still another application for the technology of this invention couldencompass the switching of a dual frequency phone to a second frequencybased on exact geographic location (EGL) of the communication device(CD). An example of this would be switching from 800-900 MHz to 2 GHzfrequencies used in the upcoming PCS system. This would be useful forthe commuter who wants PCS for his Communications Device (CD) in thecity and to be able to roam out of PCS territory into cellularterritory. It may even come to the time when subscribers are given rateplans that correspond to different zones, such as a 2000 foot perimeterof their residence which would be billed at a residence rate, and bebilled at a Home market rate beyond that. Still further, when thesubscriber enters into the geographic zone of his or her employer, theMTSO will forward his business communication processes to hiscommunication device (CD), all based on his present exact geographiclocation. This could be an important competitive advantage to a serviceprovider that owned the 900 MHz in one area and the 2000 MHz rights in asecond area. For example, FIG. 16 shows service provider A, which ownsthe license to 2000 MHz in territory 1, the 900 MHz license in territory2 and the 2000 MHz license in territory 3. When mobile unit CDX travelson roadway XR, it will pass through all through all three territories.The service provider would like to handle all the billing revenue forits subscribers traveling through territory 2, but does not have the2000 MHz license in that area. The communication device CDX is thereforeinstructed to retune to 900 MHz in territory 2 because System A doeshave rights to communication processes in territory 2 at the 900 MHzfrequency. This allows System A to by pass System B even though theSystem B is a 2000 Mhz service provider adjacent to two System Aterritories.

The preferred means for establishing exact geographic location (EGL) isa satellite communication system such as discussed in the incorporatedmaterial. However, other means, including, but not limited to,triangulation and the like, can be used without departing from the scopeof the present invention.

It is understood that while certain forms of the present invention havebeen illustrated and described herein, it is not to be limited to thespecific forms or arrangements of parts described and shown.

While the present invention has been illustrated by a description ofvarious embodiments and while these embodiments have been described inconsiderable detail, it is not the intention of the applicants torestrict or in any way limit the scope of the appended claims to suchdetail. Additional advantages and modifications will readily appear tothose skilled in the art. The invention in its broader aspects istherefore not limited to the specific details, representative apparatusand method, and illustrative example shown and described. Accordingly,departures may be made from such details without departing from thespirit or scope of applicant's general inventive concept.

1. A method of providing emergency call information for a mobile unit,comprising the steps of: obtaining a mobile unit identification numberfor the mobile unit via a cellular communication system comprising aplurality of networked antennas in communication with a plurality ofmobile units; acquiring positional data for the mobile unitcorresponding to an exact geographic location of the mobile unit via thecellular communication system; and providing emergency call informationto an emergency service, the emergency call information comprising atleast the positional data.
 2. The method of claim 1, wherein theemergency call information further comprises information based on themobile unit identification number.
 3. The method of claim 1, furthercomprising the steps of: storing geographical location data for aplurality of emergency service locations; and selecting one of theemergency service locations based on a comparison of the positional datato the geographical location data.
 4. The method of claim 3, wherein theemergency call information further comprises information based on themobile unit identification number.
 5. A method of providing an emergencyservice for a mobile unit in a cellular communication system comprisinga plurality of networked antennas in communication with a plurality ofmobile units, comprising the steps of: acquiring an exact geographiclocation of a mobile unit in communication with at least one antenna;designating a provider of an emergency service for the mobile unit basedon the exact geographic location; and routing the exact geographiclocation to the designated provider.
 6. The method of claim 5, whereinthe exact geographic location is acquired using a global positioningsystem.
 7. The method of claim 5 wherein the exact geographic locationis acquired using triangulation.
 8. The method of claim 5, furthercomprising the steps of: storing geographical location data forproviders of the emergency service; and comparing the exact geographiclocation to the geographical location data as a basis to designate theprovider of the emergency service.
 9. A method of making emergency calldecisions in a cellular telephone system having a plurality of cellsites at various geographic locations comprising: a) providing a mobileunit which can be located at various and changeable geographiclocations; b) receiving a call from the mobile unit requesting emergencyservice via a cellular telephone system; c) determining the exactgeographic location of the mobile unit from which the call is received;d) storing geographic data in the cellular telephone system and whichare required to complete the call requesting emergency service; e)comparing the exact geographic location of the mobile unit placing thecall requesting emergency service to the stored geographic data; and f)automatically routing the mobile unit call requesting emergency serviceto an emergency service based on the comparison regardless of cell sitelocation.
 10. The method of claim 9 wherein the exact geographiclocation of the mobile unit is constantly updated.
 11. Atelecommunications system, comprising: a data storage system forrecording a geographic location associated with a mobile unitidentification number, and an updating system responsive to aninaccuracy in the geographic location associated with the mobile unitidentification number that exceeds an interval defined by said updatingsystem, and in response thereto updating said data storage system toidentify an updated geographic location for said mobile unitidentification number, wherein the updated geographic location is anexact geographic location provided to an emergency service.
 12. Thesystem of claim 11, wherein the emergency service comprises a pluralityof emergency service locations and the exact geographic location isprovided to a selected one of the emergency service locations based onone of a recorded and updated geographic location.
 13. A cellularcommunications system comprising: a cellular communication networkcomprising a plurality of cell sites and a plurality of mobile units,for radio frequency communication between said cell sites and mobileunits, at least one of said cell sites receiving an identification of aspecific mobile unit, said cellular communication network communicatingwith said specific mobile unit via a cell site chosen based upon signalstrength, and a positioning system obtaining a position for saidspecific mobile unit identifying an exact geographic location of thespecific mobile unit, and forwarding said exact geographic location andspecific mobile unit identification for use in a subsequent service,wherein the subsequent service comprises a plurality of servicelocations and said exact geographic location is forwarded to one of saidservice locations based on stored data indicating a geographic locationof the mobile unit.
 14. The system of claim 13, wherein the subsequentservice is an emergency service.